add to idnex array list java code example

Example 1: java add element to existing array

//original array
String[] rgb = new String[] {"red", "green"};
//new array with one more length
String[] rgb2 = new String[rgb.length + 1];
//copy the old in the new array
System.arraycopy(rgb, 0, rgb2, 0, rgb.length);
//add element to new array
rgb2[rgb.length] = "blue";
//optional: set old array to new array
rgb = rgb2;

Example 2: java arraylist add

//create ArrayList
ArrayList<String> arrayList = new ArrayList<String>();
//add item to ArrayList
arrayList.add("item");
//check if ArrayList contains item (returns boolean)
System.out.println(arrayList.contains("item"));
//remove item from ArrayList
arrayList.remove("item");